<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  <div id="app">
    {{ 100 | currency}}
    {{ 400 | currency('$')}}
  </div>
  <script src="./vue.js"></script>
  <script>
    Vue.filter('currency', (v, sign='￥') => {
      console.log(v);
      return sign + v
    })
    const vm = new Vue({
      el: '#app'
    })
  </script>
</body>
</html>